Filter Cartridge and Apparatus for the Filtration of Liquids

ABSTRACT

The invention describes an apparatus for the filtration of liquids and an associated filter cartridge  100,  the correct seating of which is ensured and can be established by the user. The apparatus is characterized in that the inlet funnel  10  has at least one first fixing means  30  below the receiving opening  13,  and in that the filter cartridge  100  has at least one second fixing means  130  below and at a distance from the sealing rim  160,  which second fixing means, when the filter cartridge  100  is being fitted into the receiving opening  13,  interacts with the first fixing means  30.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an apparatus for the filtration of liquids. Theinvention also relates to a filter cartridge for an apparatus of thistype.

2. Description of the Related Art

Filter cartridges are to be understood as meaning on the one handcartridges which have a screen-like formation for mechanical filtration.On the other hand, filter cartridges are also to be understood asmeaning cartridges which, in addition to a screen-like formation,contain at least one filter medium, e.g. in granule form, which is usedfor the chemical and/or mechanical removal of organic and/or inorganiccontaminants and/or to lower the levels of such contaminants. Filtercartridges equipped in this way therefore allow non-mechanicalfiltration, which may be combined with mechanical filtration. Thesefilter cartridges are used to optimize water, the term optimizationbeing understood as meaning mechanical and/or non-mechanical filtration.This includes, for example, softening and decalcification of drinkingwater.

A very wide range of embodiments of apparatuses for the filtration ofliquids are known.

By way of example, there are filter apparatuses with spherical filtercartridges, which are screwed onto the inlet funnel from below by meansof a bayonet catch, as described in WO 2004/014519 A2.

DE 199 05 601 A1 has disclosed an apparatus for the treatment ofliquids, having an inlet funnel which has a receiving opening with asealing rim. The filter cartridge is likewise fitted into the receivingopening from below and is pressed into the receiving opening by means ofa separate securing ring. For this purpose, the filter cartridge isprovided with a groove on the cartridge upper part below the sealingrim; the lower portion of the securing ring engages in this groove. Theupper portion of the securing ring is guided in a groove of a connectionpiece formed integrally on the funnel base. The filter cartridge iscomplex to install and remove, requiring particular skill on the part ofthe operator.

Other embodiments provide for the inlet funnel to have, in its basewall, a receiving opening, into which the filter cartridge is fittedfrom above. The filter cartridge generally has a conical sealing rim,which bears against the edge of the receiving opening. The filtercartridge may become tilted during insertion, so that the intendedsealing position is not adopted.

DE 199 158 29 A1 has disclosed a filter cartridge and an apparatus fortreating liquids, in which the sealing rim has additional latchingmeans, which interact with corresponding latching means in the region ofthe opening in the base of the inlet funnel. The latching means arebrought into engagement with one another by a rotational movement.

In this embodiment, the filter cartridge is held only at the edge and islocated in the filtrate space. If the apparatus is a kettle, therefore,the filter cartridge is also in the boiling space, which means that thefilter cartridge could be damaged during the heating of the filteredliquid. Therefore, it is desirable for the filter cartridge to bearranged such that it is shielded from the filtrate space or boilingspace.

Inlet funnels with a receiving chamber for the filter cartridge are usedto remedy this problem. In this design too, the conical sealing rim ofthe filter cartridge bears against the rim of the receiving opening inthe base wall of the inlet funnel.

The peripheral and base wall of the filter cartridge is arranged at adistance from the peripheral and base wall of the receiving chamber, sothat during filtration, although filtered liquid can collect in thisintermediate space, this liquid does not limit the quantitative flowthrough the apparatus. An outflow opening provided with a closureelement is located in the base wall of the receiving chamber.

DE 198 46 583 A1 has disclosed a water filter device of this type, witha collection can and a heating element. The inlet funnel has a receivingchamber, into which the filter cartridge is fitted from above. Thereceiving chamber is formed by a filter insert, which may be fixedlyconnected to the inlet funnel or can be fitted into the receivingopening. The filter insert is matched to the conical shape of the filtercartridge and forms a guide element for the filter cartridge. Since theperipheral wall of the filter cartridge bears against the filter insertover its full surface, the two components can only be separated from oneanother with difficulty, in particular if the user pushes the filtercartridge too deep into the filter insert. On account of the fact thattwo conical surfaces are sliding along one another, it is not clear tothe user when he has reached the limit position which is required foroptimum seating of the filter cartridge and defines the sealing positionof the filter cartridge.

U.S. Pat. No. 4,020,350 describes a filter system which is connected toa water pipe via two connections. The filter system comprises a housingupper part and a housing lower part, which are screwed together afterthe filter cartridge has been fitted. The cover and base wall of thefilter cartridge have cup-shaped indentations, in which correspondinglyshaped connection pieces of the housing parts for supplying theunfiltered liquid and removing the filtered liquid, engage. To changethe filter cartridge, the two housing parts have to be unscrewed.

In all the known filter apparatuses, it is necessary for the filtercartridge to be matched to the desired quantitative flow.

BRIEF SUMMARY OF THE INVENTION

It is an object of the invention to provide a filter cartridge and anapparatus for the filtration of liquids with which correct seating ofthe filter cartridge is ensured and can be established by the user.

This object is achieved by an apparatus in which the inlet funnel has atleast one first fixing means below the receiving opening, and the filtercartridge has at least one second fixing means below and at a distancefrom the sealing rim; when the filter cartridge is being fitted into thereceiving opening, the at least one second fixing means interacts withthe first fixing means.

The filter cartridge can preferably be fitted into the receiving openingin its axial direction.

The fixing means are arranged in such a manner that during interactionthey define the sealing position of the filter cartridge, i.e. when thefixing means interact, the sealing rim of the filter cartridge in itsintended position bears against the edge of the receiving opening.

The interaction of the fixing means is associated with a resistance,which is perceptible to the user when he is fitting the filter cartridgeand indicates to the user that the intended position of the filtercartridge has been reached.

Since the fixing means define the sealing position of the filtercartridge, it is advantageous if the distance between sealing rim andfixing means is selected to be as great as possible. This prevents thefilter cartridge from tilting or being incorrectly positioned.

Therefore, the second fixing means are preferably arranged on the lowerhalf, preferably in the bottom third, of the filter cartridge, inparticular in the region of the base wall of the filter cartridge.

The first and/or second fixing means may be spacer elements and/or guideelements and/or latching elements. This means that a fixing means canperform one or more functions, and that it is also possible for aplurality of fixing means of different configurations to be realized inan apparatus.

The fixing means are preferably projections or recesses. The projectionsor recesses may be cylindrical, conical or frustoconical in form. Theseforms also include, for example, indentations and protuberances orbeads.

In the case of latching elements, latching bosses, latching recesses orannular beads are preferred.

In the simplest case, the fixing means may be spacer elements. By way ofexample, at least one outwardly facing projection may preferably beformed integrally on the base wall of the filter cartridge as secondfixing means, which projection, during fitting of the filter cartridge,is seated on a holding element which is arranged on the inlet funnel andforms the first fixing means.

The first fixing means may, for example, also be the base wall of areceiving chamber arranged at the inlet funnel.

Conversely, by way of example, it is also possible for the holdingelement, which may form the base wall of the receiving chamber, to haveat least one inwardly facing projection, which interacts with the basewall of the filter cartridge, which in this case forms the second fixingmeans.

The fixing means may also be guide elements, which means that the filtercartridge is guided into its intended position when it is being fitted.By way of example, projections and recesses, in particular indentationson the filter cartridge and on the holding element which, by way ofexample, may be cylindrical, conical or frustoconical in form, aresuitable for this purpose.

According to a further embodiment, the fixing means may also be latchingelements which engage in one another as they interact. The latching orsnapping into place is generally associated with a noise which indicatesto the user that the filter cartridge has reached its intended position.

The fixing means are preferably matched to one another in such a mannerthat fitting the filter cartridge in the axial direction is sufficientto bring the fixing means together. Therefore, there is no need eitherfor rotary, tilting or other movements of the filter cartridge or foradditional components, such as securing rings or the like, which overallmakes insertion of the filter cartridge user-friendly.

Furthermore, the fixing means are matched to one another in such amanner that they can be detached from one another without particulareffort when the filter cartridge is being exchanged.

This is achieved, inter alia, by the contacting surfaces of the fixingmeans being kept small in the case of guide elements, in order toprevent the filter cartridge from jamming or sticking in place.

If the fixing means are designed as latching elements, the latching orclamping forces are kept low, in such a manner that the filter cartridgecan be removed by simply being pulled out of the receiving opening inthe axial direction. The latching elements are therefore preferablydesigned in such a manner that an axial movement of the filter cartridgeis sufficient to fit or remove it.

It is preferable for the first fixing means to be arranged on a holdingelement arranged at the underside of the funnel base wall. A holdingelement of this type may be designed in various ways. A holding elementin the form of a holding bracket which spans the receiving opening belowthe latter is preferred.

According to a further embodiment, the holding element may be areceiving chamber which is arranged in the funnel base wall, has atleast one outflow opening and has a base wall and a peripheral wall.

Preferably, the base wall of the receiving chamber has at least onefirst indentation, and the base wall of the filter cartridge has atleast one second indentation, which engages over the first indentation.These two indentations may interact in a sliding manner and thereby formguide elements. Moreover, these indentations may also be provided withlatching elements which engage in one another when the filter cartridgeis being fitted.

Preferably, the first indentation is a cylindrical or frustoconicalhollow body, which is formed integrally on the base wall of thereceiving chamber, faces inwards and has at least one inwardly facingfirst bead, which is in the shape of an arc of a circle and leaves clearat least one outflow opening, arranged on its free edge, wherein anoutwardly facing mandrel, which engages in the cylindrical orfrustoconical hollow body when fitting the filter cartridge, is arrangedin the second indentation.

In this embodiment, the first guide element is formed by the at leastone bead, which is in the form of an arc of a circle and slides alongthe outer side of the mandrel when the filter cartridge is beinginserted. The bead does not extend over the entire inner periphery ofthe hollow body, and consequently a free space remains which, afterfitting of the mandrel, which represents the second guide element, formsthe outflow opening. A plurality of arcuate beads or bead segments maybe arranged at a distance from one another in the peripheral direction,so that a plurality of outflow openings are created.

According to a further embodiment, the mandrel has at least one secondbead in the shape of an arc of a circle on its outer side, which secondbead engages behind the first bead during fitting of the filtercartridge. In this case, the first and second beads form latchingelements.

It is preferable for the hollow body and the mandrel each to be arrangedcentrally. This arrangement has the advantage that in each case only onefixing means is required, and as a result the space required for thefixing means can be kept small, and consequently more volume isavailable for the filter medium.

It is preferable for the receiving chamber to have the first indentationin the region of base and peripheral wall and for the filter cartridgeto have the second indentation likewise in the base and peripheral wall.

The first and second indentations may preferably be cuboidal in form, sothat the two indentations each have two side walls, one end wall and onecovering wall. The two indentations may be in the form of guide elementswhich engage in one another or slide into one another.

It is advantageous if the first indentation has first latching means ontwo side walls and the second indentation has second latching means ontwo side walls. This embodiment has the advantage that it is possible torealize greater latching forces, for example in devices in which wateris heated. The two indentations may have different dimensions, whichbrings the advantage that there is only one possible position for thefilter cartridge.

The fixing means allow accurate positioning of the filter cartridge, sothat not only is the optimum position of the sealing rim at thereceiving opening ensured, but also a defined distance can be setbetween the filter cartridge and the wall of the receiving chamber. Thecross section of the flow passage between outlet opening of the filtercartridge and outflow opening of the receiving chamber can thus likewisebe set in a targeted way.

This also enables a throttling device to be arranged between the outletopening in the filter cartridge and the outflow opening in the receivingchamber.

The quantitative flow through the filter cartridge substantially dependson the type of filter medium and the size of the outlet opening(s) inthe filter cartridge. Depending on the particular application, forexample in filter systems of which a high performance is demanded of thefilter medium, it may be necessary to reduce the quantitative flow whichis predetermined by the filter cartridge. To achieve this, hitherto thecartridge has been modified, i.e. suitable filter cartridges had to beproduced and kept in stock for every desired quantitative flow. Theadvantage of the throttling device is firstly that only one type offilter cartridge is required, and the quantitative flow can be set byselecting a suitable receiving chamber or a suitable inlet funnel.

Secondly, it is advantageous with this configuration that if thecartridge is not present the appliance can be operated without any flowrestrictions.

It is preferable for the throttling device to be designed in such amanner that the quantitative flow delivered by the filter cartridge canbe reduced by more than 0 up to 95%, in particular by 10 to 80%,particularly preferably by 20 to 70%.

It is preferable for the filter cartridge to be arranged in the regionbetween outlet opening and outflow opening, at a distance from theperipheral wall and/or base wall of the receiving chamber, therebyforming a flow passage. The minimum cross section of the flow passagethen forms the throttling device.

The cross section of the flow passage can be accurately set by thefixing means.

A preferred embodiment provides for at least one fixing means to formthe throttling device. By way of example, if a spacer element formedintegrally on the filter cartridge or the receiving chamber is arrangedin the flow passage, the cross section is reduced at this location. Theaction of the throttling device can easily be set by means of thedimensions of one or more spacer elements of this type.

It is preferable for the indentations of filter cartridge and receivingchamber to be arranged at a distance from one another at least insubregions, so that a reduced cross section of flow, which forms thethrottling device, is set between the indentations.

Alternatively, the outflow opening or outflow openings may form thethrottling device, in which case the cross section of the outflowopening/openings is smaller than the cross section of the outletopening/outlet openings in the filter cartridge.

A preferred embodiment provides for the cross section of the outflowopening/outflow openings defined by the bead or beads on the cylindricalor frustoconical hollow body to be selected in such a way thatthis/these outflow opening(s) has/have a throttling action.

For a predetermined filter cartridge, the throttling device may beadjustable by selecting a receiving chamber of suitable dimensions orwith a suitable cross section of the outflow opening.

The desired quantitative flow can therefore be set by means of the inletfunnel, which is advantageous in that the inflow funnel, unlike thefilter cartridge, does not represent a consumable item. The consumableitem formed by the filter cartridge only has to be produced and kept instock in one design, and the quantitative flow can be defined by theselection of inlet funnel. This makes it possible to significantlyreduce the manufacturing costs of the apparatus and the costs of spares.

It is preferable for the outflow opening in the receiving chamber to bearranged above the outlet opening in the filter cartridge, so as tocreate a siphon-like arrangement. A siphon-like arrangement of this typehas the advantage, in particular in conjunction with the throttlingdevice, that the filter medium is kept moist even in the event of breaksin filtration, and therefore its full operational readiness is ensuredeven without renewed conditioning.

The presence of fixing means also allows a new type of configuration ofthe sealing rim of the filter cartridge, allowing the correct seating ofthe filter cartridge and the sealing position to be improved further.

For this purpose, provision is made for the sealing rim to be asnap-action rim which is connected to one of the two cartridge parts viaan integral hinge, it being possible for the snap-action rim to beflipped from a first, lower snap-action position into an upper, secondsnap-action position and vice versa, and for the funnel base wall tohave a sealing seat, which surrounds the receiving opening and intowhich the snap-action rim snaps in its second position.

With the snap-action rim in its lower snap-action position, the filtercartridge is fitted into the receiving opening from above and presseddownwards until the snap-action rim flips upwards and in the processsnaps into the sealing seat. The sealing seat is matched to thesnap-action rim in such a manner that when the snap-action rim hassnapped into place, the filter cartridge bears in a sealing manneragainst the edge of the receiving opening and is fixed in place.

The snap-action indicates to the user that the filter cartridge hasadopted its predetermined sealing position. This prevents both incorrectpositioning by the user and slipping of the filter cartridge duringtransport.

To remove the filter cartridge, it is simply pulled out upwards, duringwhich operation the snap-action rim flips into its lower snap-actionposition.

The snap-action rim is preferably formed by a flat edge strip whichextends outwards in the radial direction.

In this embodiment, fixing means in the form of guide elements aresufficient. Here, fixing means in the form of latching elements could bedisadvantageous since in the event of what is known as double latchingat the sealing rim and, for example, in the region of the base, thetolerances which have to be observed make production costscorrespondingly high.

In the case of a filter cartridge in which the cartridge upper part hasan outwardly facing first securing flange and the cartridge lower parthas an outwardly facing second securing flange, via which the twocartridge parts are connected to one another, the snap-action rim ispreferably connected to one of the two securing flanges by way of theintegral hinge.

The sealing seat at the inlet funnel is matched to this snap-action rim.It is preferable for the sealing seat to merge into a conicallyprotruding rim section with an inwardly open abutment section, on whichthe outer edge of the snap-action rim engages.

The abutment section may be a groove or a step with at least oneinclined surface.

The filter cartridge, which can be fitted into the inlet funnel and hasa cartridge upper part with at least one inlet opening, a cartridgelower part with at least one outlet opening and a sealing rim, ischaracterized by least one fixing means arranged below and at a distancefrom the sealing rim.

The fixing means at the filter cartridge is preferably a spacer elementand/or guide element and/or latching element. The fixing means may berecesses and projections, the projections or recesses preferably beingcylindrical, conical or frustoconical in form. The latching element maybe a latching boss, a latching recess or an annular bead.

The fixing means is preferably arranged in the region of the lower halfof the filter cartridge, preferably in the region of the bottom thirdand in particular in the region of the base wall of the filtercartridge.

The cartridge lower part has at least one indentation, with an outwardlyfacing mandrel preferably being arranged in the indentation.

According to a further embodiment, the indentation may also be cuboidalin form.

The sealing rim is preferably a snap-action rim which is connected toone of the two cartridge parts via an integral hinge, it being possiblefor the snap-action rim to be flipped from a first, lower snap-actionposition into an upper, second snap-action position and vice versa.

If the filter cartridge has a sealing flange on its upper and lowerparts, the snap-action rim is preferably connected to one of the twosecuring flanges by way of the integral hinge.

The snap-action rim is preferably formed by a flat edge strip which isdirected radially outwards.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Exemplary embodiments of the invention are explained in more detailbelow with reference to the drawings, in which:

FIGS. 1 a, b show vertical sections through an inlet funnel with fittedfilter cartridge in accordance with two embodiments,

FIG. 2 shows a perspective view, partially in section, of an inletfunnel in accordance with a further embodiment,

FIG. 3 shows a vertical section through an inlet funnel with fittedfilter cartridge in accordance with a further embodiment, before thefilter cartridge has reached its limit position,

FIG. 4 shows a section on line F-F through the apparatus shown in FIG.3,

FIG. 5 shows an enlarged sectional illustration of the region of the twoindentations in accordance with FIG. 3,

FIG. 6 shows an enlarged sectional illustration of the region of the twoindentations after the filter cartridge has been fitted and positioned,

FIG. 7 a shows a plan view of the frustoconical hollow body inaccordance with FIG. 3,

FIG. 7 b shows a plan view of a frustoconical hollow body in accordancewith the a further embodiment,

FIG. 8 shows a vertical section through the frustoconical hollow body online H-H in FIG. 7 b,

FIG. 9 shows an enlarged sectional illustration of the lower region ofthe two indentations in accordance with a further embodiment, on lineG-G through the frustoconical hollow body in FIG. 7 a,

FIG. 10 shows a vertical section through a filter cartridge,

FIG. 11 shows a plan view of the filter cartridge shown in FIG. 10,

FIG. 12 shows an enlarged sectional illustration of an edge region ofthe filter cartridge illustrated in FIGS. 10 and 11,

FIG. 13 shows an enlarged sectional illustration of a region of thereceiving opening in the inlet funnel,

FIG. 14 shows an enlarged sectional illustration of the region of thereceiving opening in the inlet funnel with initially positionedsnap-action rim of a filter cartridge,

FIG. 15 shows an enlarged illustration of the region of the receivingopening of an inlet funnel with the snap-action rim of the filtercartridge snapped into position,

FIG. 16 shows a vertical section through the region of the receivingopening in the inlet funnel in accordance with a further embodiment,

FIG. 17 shows a vertical section through an inlet funnel with a fittedfilter cartridge in accordance with a further embodiment,

FIG. 18 shows a section on line B-B through the apparatus shown in FIG.17,

FIG. 19 shows an enlarged sectional illustration of the region of theoutflow opening of the apparatus shown in FIG. 17.

DETAILED DESCRIPTION

FIG. 1 a illustrates a vertical section through an inlet funnel 10 withfitted filter cartridge 100 . The inlet funnel 10 has a peripheral wall11, which merges into a funnel base wall 12 which has a receivingopening 13. A receiving chamber 14, which once again has a peripheralwall 15 and a base wall 16, extends downwards from the receiving opening13 as holding element 20.

The filter cartridge 100 is fitted into this receiving chamber 14axially from above; the filter cartridge 100 comprises a cartridge upperpart 101 and a cartridge lower part 110. The cartridge upper part 101 isconfigured in the shape of a roof and has inlet openings 102. A sealingrim 160, which bears against the sealing seat 60 of the inlet funnel 10in the region of the receiving opening 13, is provided in the connectionregion of cartridge upper part 101 and cartridge lower part 110.

The cartridge lower part 110 of the filter cartridge 100 has aperipheral wall 111 and a base wall 112, in which outflow openings 113are arranged.

The receiving chamber 14 is configured in such a manner that theperipheral wall 111 of the filter cartridge 100 is arranged at adistance from the peripheral wall 15 and from the base wall 16.Consequently, the filtered liquid collects in the lower region of thereceiving chamber 14 and flows away via the outflow openings 17 shown tothe right and left in the figure.

The receiving chamber 14 with the peripheral wall 15 and the base wall16 forms a holding element 20 for the filter cartridge 100. A secondfixing means 130, which in the embodiment shown here forms a spacerelement, is formed integrally in the centre of the base wall 112 of thefilter cartridge 100. This second fixing element 130 bears against theinner side of the base wall 16, which therefore performs the function ofa first fixing element 30.

The filter cartridge 100 is fitted into and removed from the receivingchamber 14 of the inlet funnel 10 in the axial direction, as indicatedby the double arrow. When the limit position provided during fitting isreached, the second fixing means 130 bears against the first fixingmeans 30, i.e. the base wall 16 of the receiving chamber 14. Theoperator notices this as a result of the resistance which then occurs,which indicates to the operator that the limit position has beenreached. In this limit position, the sealing rim 160 bears in a sealingmanner against the sealing seat 60 of the receiving opening 13. As aresult, the optimum position of the filter cartridge 100 has beenreached.

FIG. 1 b illustrates a further embodiment of the apparatus, whichdiffers from the apparatus shown in FIG. 1 a by virtue of the fact thattwo first fixing means 30, in the form of indentations 31 designed asspacer elements, are formed integrally on the inner side of the basewall 16. The base wall 112 of the filter cartridge 100 bears againstthese two spacer elements 30.

In this embodiment, the base wall 112 performs the function of thesecond fixing means 130.

The two first fixing means 30 are arranged in the flow passage 201between the outlet openings 113 and the outflow openings 17 and at thislocation reduce the cross section of flow. Depending on the particularconfiguration and dimensions, the fixing elements 30 in each case form athrottling device 200.

FIG. 2 illustrates a further embodiment of an inlet funnel 10, whichdoes not have a receiving chamber 14, but rather instead, as holdingelement 20, has a holding bracket 21 which comprises the twosubstantially vertical limbs 22 a, b and a cross-bar 23. This holdingbracket 21 spans the receiving opening 13 below the receiving opening13, so that a filter cartridge (not shown) can be fitted. The dimensionsof the holding bracket 21 are matched to the dimensions of the filtercartridge 100 to be fitted.

In the central region, the cross-bar 23 has a first fixing element 30 inthe form of a first indentation 31. This indentation 31 is conical inform and extends vertically upwards. The associated filter cartridge 100(not shown), in the region of its base wall, has a corresponding conicalor frustoconical indentation (second indentation 130), so that the twofixing elements interact during fitting of the filter cartridge 100 inthe axial direction, in such a way as to guide the filter cartridge. Inthis configuration, the fixing elements 30, 130 serve as spacer elementsand guide elements.

FIG. 3 illustrates a vertical section through a further embodiment ofthe apparatus. The inlet funnel 10, of which the upper part has beenomitted for the sake of clarity, has a first indentation 31, which isdesigned a frustoconical hollow body 32, arranged in the centre of itsbase wall 16. A bead 34 in the form of an arc of a circle is formedintegrally on the inner side of the free edge 33 of the hollow body 32,which bead 34, as illustrated in FIG. 7 a, does not form a continuousring, but rather has a free space 18 which forms the outflow opening 17after the filter cartridge has been fitted.

In its base wall 112, the filter cartridge 100 likewise has anindentation 131 in which a mandrel 132, which extends verticallydownwards, is formed integrally. When the filter cartridge 100 is beingfitted into the receiving chamber 14, the mandrel 132 engages in thefrustoconical hollow body 32, with the outer surface 133 of the mandrel132 sliding along the bead 34. In this embodiment, the mandrel 132 andthe bead 34 form first and second fixing means 30, 130 which serve asguide elements. The outflow opening 17 is formed between the outersurface 133 of the mandrel 132 and the wall 35 of the hollow body 32.

FIG. 3 illustrates the filter cartridge 100 at the start of the fittingoperation. The sealing rim 160, which in the embodiment shown here isdesigned as a snap-action rim 161, is therefore not yet in its limitposition. The snap-action rim 161 will be described separately below.

FIG. 4 illustrates a section on line F-F through the apparatus shown inFIG. 3. It can be seen from this figure that the mandrel 132 bearsagainst the bead 34 in the form of an arc of a circle and at thislocation also forms a seal apart from the outflow opening 17 (which isnot visible in FIG. 4).

FIG. 5 illustrates an enlarged view of the lower region of filtercartridge 100 and receiving chamber 14, illustrating the fitting statein accordance with FIG. 3. The second indentation 131 has a base wall134 a and an annular wall 134 b, which extends upwards from the basewall 112. Spacer ribs 139 are formed integrally on the underside of thebase wall 134 a.

In FIG. 6, the filter cartridge 100 has reached its limit position andtherefore its sealing position. A flow passage 201 is formed between thebase wall 112 of the filter cartridge 100 and the base wall 16 of thereceiving chamber 14 and merges, in the region of the two indentations31, 131, into a rising annular passage 202 which is formed between wall35 of the hollow body 32 and the annular wall 134 b. The cross sectionof the annular passage 202 is smaller than that of the flow passage 201,so that a throttling device 200′ is formed.

However, the annular passage 202 only forms the throttling device 200′if the outflow opening 17 has a significantly larger cross section. Inthe embodiment shown here, there is only a single outflow opening 17,which has a smaller cross section of flow than the cross section of theannular passage 202, and consequently the outflow opening 17 can beequated to the throttling device 200′. The two fixing elements 30, 130in the form of the annular bead 34 and in the form of the mandrel 132therefore form the throttling device 200 in the assembled state. Thespacer ribs 139 bear against the end face 39 of the hollow body 32 andtherefore, as spacer elements, form second fixing means 130.

FIG. 7 b illustrates a further embodiment of the hollow body 32, whichdiffers from the embodiment illustrated in FIG. 7 a by virtue of thefact that a total of four beads 34 in the form of arcs of a circle arearranged spaced apart from one another, so that free spaces 18 for theoutflow openings 17 in each case remain between the beads 34. Whetherthe combination of these outflow openings form a throttling device 200depends on the cross-sectional dimensions of the flow passage, inparticular of the annular passage 202 in the region of the frustoconicalhollow body 32.

FIG. 8 illustrates the hollow body 32 in vertical section on line H-H inFIG. 7 b. The triangular shape of the arcuate beads 34 has the advantageof minimizing the surface area of the contact surface with the mandrelthat is to be introduced, so that the frictional forces arecorrespondingly low and the filter cartridge can be fitted and removedwithout difficulty.

FIG. 9 illustrates a further embodiment, in which the mandrel 132 islikewise provided with a bead (second bead) 135 on its outer surface. Inthis case, the section through the frustoconical hollow body 32 is takenon line G-G from FIG. 7 a. When the filter cartridge 100 is beingfitted, the mandrel 132 engages in the hollow body 32, with the annularbead 135 engaging behind the bead 34 when the spacer ribs 139 arebearing against the end face 39. Free spaces (not visible in thisfigure) are provided between the spacer ribs 139, so that the liquid canflow to the outflow opening 17. In this embodiment, the beads 34 and 135form latching elements, and the spacer ribs 139 form spacer elements,with the end face 39 of the hollow body 32, as first fixing means 30,forming a stop.

FIG. 10 illustrates a vertical section through a filter cartridge 100 inorder to explain the function of the sealing rim 160 in conjunction withthe following figures. The cartridge upper part 101 has a securingflange 120, which is joined to the securing flange 121 of the cartridgelower part 110, preferably by welding. The securing flange 120 extendsradially outwards and has an integral hinge 162, via which thesnap-action rim 161 is attached in jointed fashion. The snap-action rim161 is formed by a flat edge strip directed radially outwards.

FIG. 10 illustrates the snap-action rim 161 in its lower position. Asillustrated in FIG. 11, the snap-action rim 161 is designed to runcontinuously all the way around, as is the integral hinge 162. A deadcentre has to be overcome when the snap-action rim is being flipped froma lower snap-action position into an upper snap-action position.

FIG. 12 illustrates the snap-action rim 161 on an enlarged scale. Theintegral hinge 162 is formed as an encircling groove 163 on theunderside of the securing flange 120.

FIG. 13 illustrates the corresponding receiving opening 13 in sectionand on an enlarged scale. The sealing seat 60 with which the snap-actionrim 161 interacts during fitting of the filter cartridge has a conicallyprotruding edge section 61, which merges into the abutment section 62,which in the embodiment shown in FIG. 13 is designed as a groove 63. Thegroove 63 is open on the radially inner side, so that the snap-actionrim 161 can engage therein, as can be seen in the following FIGS. 14 and15.

FIG. 14 illustrates the start of the snap-action process. Thesnap-action rim 161 is still in its lower position and is engagingagainst the conically protruding edge section 61.

As the filter cartridge 100 continues to be lowered, the snap-action rim161 is moved into its upper position, with the outer edge 164 of thesnap-action rim 161 engaging in the groove 63, as illustrated in FIG.15. There is no need for the whole of the surface of the snap-action rim161 to bear against the surface 61. Sealing is effected in the region ofthe groove 63.

FIG. 16 illustrates an alternative to the groove 63. The abutmentsection 62 comprises a step 64 which has a substantially horizontalsurface 66 and an inwardly inclined surface 65.

FIG. 17 illustrates a vertical section through an inlet funnel 10 withfitted cartridge 100 in accordance with a further embodiment. The filtercartridge 100 has a conventional sealing rim 160, which bears againstthe sealing seat 60 in the region of the receiving opening 13. Twocuboidal indentations 36 and 37 are formed integrally in the peripheralwall 15 and the base wall 16 of the receiving chamber 14. Theseindentations 36, 37 each have two side walls 40, 41 (not visible), anend wall 42 and a covering wall 43. The outflow opening 17 is located inthe end wall 42.

The cartridge 100 also has corresponding indentations 136 and 137, whichare likewise cuboidal in design, with side walls 140, 141 (not visiblein FIG. 17), end wall 142 and covering wall 143, with the mutuallycorresponding walls of cartridge and receiving chamber being arranged ata distance from one another, so that flow passages 201 are formedbetween the walls.

FIG. 18 illustrates a section on line B-B. Fixing means 30, 130 in theform of latching elements are provided in the two side walls 40, 41,140, 141 of the cuboidal indentations 36, 136. The latching elements arelatching bosses 38 which engage in corresponding latching recesses 138.

This configuration of the latching elements is to be found on bothcuboidal indentations 36, 37, 136, 137.

FIG. 19 shows an enlarged illustration of the cuboidal indentations 37,137.  10 Inlet funnel  11 Peripheral wall  12 Funnel base wall  13Receiving opening  14 Receiving chamber  15 Peripheral wall  16 Basewall  17 Outflow opening  18 Free space  20 Holding element  21 Holdingbracket  22a, b Limb  23 Cross-bar  30 First fixing means  31 Firstindentation  32 Frustoconical hollow body  33 Free edge  34 Bead in theform of an arc of a circle  35 Wall of the hollow body  36 Cuboidalindentation  37 Cuboidal indentation  38 Latching boss  39 End face  40Side wall  41 Side wall  42 End wall  43 Covering wall  60 Sealing seat 61 Conically protruding edge section  62 Abutment section  63 Groove 64 Step  65 Inclined surface  66 Horizontal surface 100 Filtercartridge 101 Cartridge upper part 102 Inlet opening 110 Cartridge lowerpart 111 Peripheral wall 112 Base wall 113 Outlet opening 120 Securingflange on upper part 121 Securing flange on lower part 130 Second fixingmeans 131 Second indentation 132 Mandrel 133 Outer surface 134a Basewall 134b Annular wall 135 Second bead 136 Cuboidal indentation 137Cuboidal indentation 138 Latching recess 139 Spacer rib 140 Side wall141 Side wall 142 End wall 143 Covering wall 160 Sealing rim 161Snap-action rim 162 Integral hinge 163 Encircling groove 164 Outer edge200, 200′ Throttling device 201 Flow passage 202 Annular passage

1. Apparatus for the filtration of liquids, having a filter cartridge (100), which includes a cartridge upper part (101) with at least one inlet opening (102), a cartridge lower part (110) with at least one outlet opening (113) and a sealing rim (160), and having an inlet funnel (10) with a peripheral wall (11), with a funnel base wall (12), in which a receiving chamber (14) is arranged having at least one outflow opening (17), said chamber having a base wall (16) and a peripheral wall (15), and with a receiving opening (13), which is arranged in the funnel base wall (12) and into which the filter cartridge (100) can be fitted from above, the sealing rim (160) of the filter cartridge (100) bearing against the edge of the receiving opening (13), characterized in that the inlet funnel (10) has at least one first latching element (30) below the receiving opening (13), and in that the filter cartridge (100) has at least one second latching element (130) in the region of the bottom third, said latching elements (30, 130), when the filter cartridge (100) is being fitted in the axial direction, interacting and defining the sealing position of the filter cartridge (100) and that the fixing forces are adjusted such that the filter cartridge (100) can be removed by being pulled out of the receiving opening (13), in the axial direction. 2-4. (canceled)
 5. Apparatus according to claim 1, characterized in that the second latching element (130) is arranged in the region of the base wall (112) of the filter cartridge (100).
 6. Apparatus according to claim 1, characterized in that the first and/or second fixing means (30, 130) are spacer elements and/or guide elements.
 7. Apparatus according to claim 1, characterized in that the latching elements (30, 130) are projections or recesses.
 8. Apparatus according to claim 7, characterized in that the projections or recesses are cylindrical, conical or frustoconical
 9. Apparatus according to claim 1, characterized in that the latching elements comprise latching bosses (38), latching recesses (138) or annular beads (34, 135). 10-12. (canceled)
 13. Apparatus according to claim 1, characterized in that the base wall (16) of the receiving chamber (14) has at least one first indentation (31), and in that the base wall (112) of the filter cartridge (100) has at least one second indentation (131), which engages over the first indentation (31).
 14. Apparatus according to claim 47, characterized in that the first indentation (31) is a cylindrical or frustoconical hollow body (32), which is formed integrally on the base wall (16) of the receiving chamber (14), faces inwards and has at least one inwardly facing first bead (34), which is in the shape of an arc of a circle and leaves clear at least one outflow opening (17), arranged on its free edge (33), and in that an outwardly facing mandrel (132), which engages in the cylindrical or frustoconical hollow body (32) when fitting the filter cartridge (100), is arranged in the second indentation (131).
 15. Apparatus according to claim 14, characterized in that the mandrel (132), on its outer side, has at least one second bead (135) in the shape of an arc of a circle, which engages behind the first bead (34) during fitting of the filter cartridge (100).
 16. Apparatus according to claim 14, characterized in that the hollow body (32) and the mandrel (132) are each arranged centrally.
 17. Apparatus according to claim 14, characterized in that the receiving chamber (14) has the first indentation (31) in the region of the base and peripheral walls (15, 16) and in that the filter cartridge (100) has the second indentation (131) likewise in its peripheral and base walls (111, 112).
 18. Apparatus according to claim 17, characterized in that the first and second indentations (31, 131) are cuboidal in form.
 19. Apparatus according to claim 17, characterized in that the first indentation (31) has first latching means on two of its side walls (40, 41), and the second indentation (131) has second latching means on two of its side walls (140, 141).
 20. Apparatus according to claim 1, characterized in that at least one throttling device (200, 200′) is arranged between the outlet opening (113) of the filter cartridge (100) and the outflow opening (17) of the receiving chamber (14).
 21. Apparatus according to claim 20, characterized in that the throttling device (200, 200′) reduces the flow quantity delivered by the filter cartridge (100) by >0%-95%.
 22. Apparatus according to claim 20, characterized in that the filter cartridge (100) is arranged in the region between outlet opening (113) and outflow opening (17), at a distance from the peripheral wall (15) and/or base wall (16) of the receiving chamber (14), with the result that a flow passage (201) is formed, and in that the minimum cross section of the flow passage (201, 202) forms the throttling device (200, 200′).
 23. Apparatus according to claim 21, characterized in that at least one fixing means or latching element (30, 130) forms the throttling device (200, 200′).
 24. Apparatus according to claim 17, characterized in that at least one throttling device (200, 200′) is arranged between the outlet opening (113) of the filter cartridge (100) and the outflow opening (17) of the receiving chamber, the throttling device (200, 200′) reduces the flow quantity delivered by the filter cartridge (100) by >0%-95%, at least one fixing means (30, 130) forms the throttling device and the first and second indentations (31, 131), at least in subregions, are arranged at a distance from one another.
 25. Apparatus according to claim 20, characterized in that the outflow opening (17) forms the throttling device (200, 200′), the cross section of the outflow opening (17) being smaller than the cross section of the outlet opening (113) in the filter cartridge (100).
 26. Apparatus according to claim 20, characterized in that, for a predetermined filter cartridge (100), the throttling device (200, 200′) can be set by selecting a receiving chamber (14) of suitable dimensions or with a suitable cross section of the outflow opening (17).
 27. Apparatus according to claim 12, characterized in that the outflow opening (17) in the receiving chamber (14) is arranged above the outlet opening (113) in the filter cartridge (100).
 28. Apparatus according to claim 1, characterized in that in that the sealing rim (160) is a snap-action rim (161), which is connected to one of the two cartridge parts (101, 110) via an integral hinge (162), it being possible for the snap-action rim (161) to be flipped from a first, lower snap-action position into an upper, second snap-action position, and vice versa, and in that the funnel base wall (12) has a sealing seat (60), which surrounds the receiving opening (13) and into which the snap-action rim (161) snaps in its second position.
 29. Apparatus according to claim 28, in which the cartridge upper part (101) has an outwardly facing first securing flange (120) and the cartridge lower part (110) has an outwardly facing second securing flange (121), via which the two cartridge parts (101, 110) are connected to one another, characterized in that the snap-action rim (161) is connected to one of the two securing flanges (120, 121) via the integral hinge (162).
 30. Apparatus according to claim 28, characterized in that the sealing seat (60) merges into a conically projecting rim section (61) with an inwardly open abutment section (62), on which an outer edge (164) of the snap-action rim (161) engages is a groove.
 31. Apparatus according to claim 30, characterized in that the abutment section (62) is a groove (63).
 32. Apparatus according to claim 30, characterized in that the abutment section (62) is a step (64) with at least one inclined surface (65).
 33. Filter cartridge which includes a cartridge upper part (101) with at least one inlet opening (102), a cartridge lower part (110) with at least one outlet opening (113) and a sealing rim (160), characterized by at least one fixing means (130) being is arranged below and at a distance from the sealing rim (160), with the cartridge lower part (110) at least being provided with one indentation (131, 136, 137).
 34. Filter cartridge according to claim 33, characterized in that the fixing means (130) is a spacer element and/or guide element and/or latching element.
 35. Filter cartridge according to claim 33, characterized in that the fixing means (130) is a projection or a recess.
 36. Filter cartridge according to claim 35, characterized in that the.
 37. Filter cartridge according to claim 34, characterized in that the latching element is a latching boss, a latching recess (138) or an annular bead (135). 38-39. (canceled)
 40. Filter cartridge according to claim 33, characterized in that the fixing means (130) is arranged in the region of the base wall (112) of the filter cartridge (100).
 41. (canceled)
 42. Filter cartridge according to claim 33, characterized in that an outwardly facing mandrel (132) is arranged in the indentation (131).
 43. Filter cartridge according to claim 33, characterized in that the indentation (136, 137) is cuboidal in form.
 44. Filter cartridge according to claim 33, characterized in that the sealing rim (160) is a snap-action rim (161) which is connected to one of the two cartridge parts (101, 110) via an integral hinge (162), it being possible for the snap-action rim (161) to be flipped from a first, lower snap-action position into an upper, second snap-action position, and vice versa.
 45. Filter cartridge according to claim 44, in which the cartridge upper part (101) has an outwardly facing first securing flange (120), and the cartridge lower part (110) has an outwardly facing second securing flange (121), via which the two cartridge parts (101, 110) are connected to one another, characterized in that the snap-action rim (161) is connected to one of the two securing flanges (120, 121) via the integral hinge (162).
 46. Filter cartridge according to claim 44, characterized in that the snap-action rim (161) is a flat edge strip which faces radially outwards.
 47. Apparatus for the filtration of liquids, having a filter cartridge (100), which includes a cartridge upper part (101) with at least one inlet opening (102), a cartridge lower part (110) with at least one outlet opening (113), and a sealing rim (160), and having an inlet funnel (10) with a peripheral wall (11), with a funnel base wall (12), in which a receiving chamber 14 is arranged having at least one outflow opening (17), said chamber having a base wall (16) and a peripheral wall (15), and with a receiving opening (13), which is arranged in the funnel base wall (12) and into which the filter cartridge (100) can be fitted from above, the sealing rim (160) of the filter cartridge (100) bearing against the edge of the receiving opening (13), characterized in that the inlet funnel (10) has at least one first fixing means (30) below the receiving opening (13), which comprises at least a first indentation (3 1) in the base wall (16) of the receiving chamber (14), that the filter cartridge (100) has at least one second fixing means (130) below and at a distance from the sealing rim (160), which comprises at least a second indentation (131) in the base wall (112) of the filter cartridge (100) engages over the first indentation (31), and that the fixing means (30, 130), when the filter cartridge (100) is being fitted in the axial direction, interacting such that the sealing position of the filter cartridge (100) is defined.
 48. Apparatus according to claim 47, characterized in that the first and/or second fixing means (30, 130) are spacer elements and/or guide elements.
 49. Apparatus according to claim 47, characterized in that the fixing means (30, 130) are projections or recesses.
 50. Apparatus according to claim 49, characterized in that the projections or recesses are cylindrical, conical or frustoconical.
 51. Apparatus according to claim 47, characterized in that the fixing means are latching elements and comprise latching bosses (38), latching recesses (138) or annular beads (34, 135).
 52. Filter cartridge which includes a cartridge upper part (101) with at least one inlet opening (102), a cartridge lower part (110) with at least one outlet opening (113) and a sealing rim (160), characterized in that at least one fixing means with the fixing means being a latching element (130) which is arranged below and at a distance from the sealing rim (160) in the region of the lower third of the filter cartridge (100).
 53. Filter according to claim 33, characterized in that the fixing means (130) is arranged in the region of the lower half of the filter cartridge (100).
 54. Filter cartridge according to claim 53, characterized in that the fixing means (130) is arranged in the region of the lower third of the filter cartridge (100).
 55. Filter cartridge according to claim 33, characterized in that the fixing means (130) is a latching element. 